regex.h

Go to the documentation of this file.

#pragma once
/*
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program; if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA
 */
#ifdef HAVE_REGEX
/** Wrappers around various regular expression libraries
 *
 * @file src/lib/util/regex.h
 *
 * @copyright 2014 The FreeRADIUS server project
 */
RCSIDH(regex_h, "$Id: 4285d25c830c41f25bd59b5fb13783806d926fe9 $")
 
#  ifdef __cplusplus
extern "C" {
#  endif
 
#include <freeradius-devel/build.h>
#include <freeradius-devel/missing.h>
#include <freeradius-devel/util/sbuff.h>
#include <freeradius-devel/util/talloc.h>
#include <freeradius-devel/util/value.h>
 
#include <stdbool.h>
#include <stdint.h>
#include <unistd.h>
 
/*
 *######################################
 *#      STRUCTURES FOR LIBPCRE2       #
 *######################################
 */
#  ifdef HAVE_REGEX_PCRE2
#    define PCRE2_CODE_UNIT_WIDTH 8
#    include <pcre2.h>
/*
 *  libpcre defines its matches as an array of ints which is a
 *  multiple of three.
 */
 
/** libpcre2 has its own matchdata struct, we wrap it so we can use talloc destructors
 *
 */
typedef struct {
        pcre2_match_data        *match_data;    //!< Match data containing the subject
                                                ///< and various match offsets.
        size_t                  used;           //!< Number of slots filled with match data.
#ifndef NDEBUG
        char const              *subject;       //!< Here for debugging purposes if we explicitly duped the string.
#endif
} fr_regmatch_t;
 
typedef struct {
        pcre2_code              *compiled;      //!< Compiled regular expression.
        uint32_t                subcaptures;    //!< Number of subcaptures contained within the expression.
 
        bool                    precompiled;    //!< Whether this regex was precompiled,
                                                ///< or compiled for one off evaluation.
        bool                    jitd;           //!< Whether JIT data is available.
} regex_t;
/*
 *######################################
 *#      STRUCTURES FOR LIBPCRE        #
 *######################################
 */
#  elif defined(HAVE_REGEX_PCRE)
#    include <pcre.h>
/*
 *  Versions older then 8.20 didn't have the JIT functionality
 *  so, gracefully degrade.
 */
#    ifndef PCRE_STUDY_JIT_COMPILE
#      define PCRE_STUDY_JIT_COMPILE 0
#    endif
/*
 *  libpcre defines its matches as an array of ints which is a
 *  multiple of three.
 */
typedef struct {
        int a;
        int b;
        int c;
} regmatch_t;
 
/** Emulates the functionality of the pcre2_match_data struct
 *
 */
typedef struct {
        regmatch_t              *match_data;    //!< Slots for matches.
        size_t                  allocd;         //!< Number of slots allocated for match data.
        size_t                  used;           //!< Number of slots filled with match data.
        char const              *subject;       //!< A local copy of the subject.
} fr_regmatch_t;
 
/** Bundles compiled regular expression structures together
 *
 */
typedef struct {
        pcre                    *compiled;      //!< Compiled regular expression.
        pcre_extra              *extra;         //!< Result of studying a regular expression.
        uint32_t                subcaptures;    //!< Number of subcaptures contained within the expression.
 
        bool                    precompiled;    //!< Whether this regex was precompiled, or compiled for one off evaluation.
        bool                    jitd;           //!< Whether JIT data is available.
} regex_t;
/*
 *######################################
 *#    STRUCTURES FOR POSIX-REGEX      #
 *######################################
 */
#  else
#    include <regex.h>
/*
 *  Allow REG_EXTENDED and REG_NOSUB to be or'd with flags
 *  if they're not defined.
 */
#    ifndef REG_EXTENDED
#      define REG_EXTENDED (0)
#    endif
 
#    ifndef REG_NOSUB
#      define REG_NOSUB (0)
#    endif
 
/** Emulates the functionality of the pcre2_match_data struct
 *
 */
typedef struct {
        regmatch_t              *match_data;    //!< Slots for matches.
        size_t                  allocd;         //!< Number of slots allocated for match data.
        size_t                  used;           //!< Number of slots filled with match data.
        char const              *subject;       //!< A local copy of the subject.
} fr_regmatch_t;
 
#  endif
 
/*
 *########################################
 *#  UNIVERSAL FUNCTIONS AND STRUCTURES  #
 *########################################
 */
 
/** The set of all flags implemented by the different regex libraries
 *
 * A specific library may not implement all these flags.  If an unsupported flag is high
 * then the library will produce an error.
 */
typedef struct {
        uint8_t global:1;                       //!< g - Perform global matching or substitution.
        uint8_t ignore_case:1;                  //!< i - Perform case insensitive matching.
        uint8_t multiline:1;                    //!< m - Multiline search.
        uint8_t dot_all:1;                      //!< s - Singleline - '.' matches everything, including newlines.
        uint8_t unicode:1;                      //!< u - Use unicode properties for character with code points
                                                ///< greater than 127.
        uint8_t extended:1;                     //!< x - Permit whitespace and comments.
} fr_regex_flags_t;
 
#define REGEX_FLAG_BUFF_SIZE    7
 
ssize_t         regex_flags_parse(int *err, fr_regex_flags_t *out, fr_sbuff_t *in,
                                  fr_sbuff_term_t const *terminals, bool err_on_dup);
 
ssize_t         regex_flags_print(fr_sbuff_t *sbuff, fr_regex_flags_t const *flags);
 
        ssize_t         regex_compile(TALLOC_CTX *ctx, regex_t **out, char const *pattern, size_t len,
                              fr_regex_flags_t const *flags, bool subcaptures, bool runtime);
int             regex_exec(regex_t *preg, char const *subject, size_t len, fr_regmatch_t *regmatch) CC_HINT(nonnull(1,2));
#ifdef HAVE_REGEX_PCRE2
int             regex_substitute(TALLOC_CTX *ctx, char **out, size_t max_out, regex_t *preg, fr_regex_flags_t const *flags,
                                 char const *subject, size_t subject_len,
                                 char const *replacement, size_t replacement_len,
                                 fr_regmatch_t *regmatch);
#endif
uint32_t        regex_subcapture_count(regex_t const *preg);
fr_regmatch_t   *regex_match_data_alloc(TALLOC_CTX *ctx, uint32_t count);
 
int             fr_regex_cmp_op(fr_token_t op, fr_value_box_t const *a, fr_value_box_t const *b) CC_HINT(nonnull);
 
#  ifdef __cplusplus
}
#  endif
#endif